basic/prioq: add prioq_peek_item()

diff --git a/src/basic/prioq.c b/src/basic/prioq.c
index cfd08d5d23223ac4164e2a19c42914c660cb28e9..76b27fa0a8e65e52c449e6e9bd009609bc0c5fc9 100644 (file)
--- a/src/basic/prioq.c
+++ b/src/basic/prioq.c
@@ -259,15 +259,14 @@ int prioq_reshuffle(Prioq *q, void *data, unsigned *idx) {
         return 1;
 }
 
-void *prioq_peek(Prioq *q) {
-
+void *prioq_peek_by_index(Prioq *q, unsigned idx) {
         if (!q)
                 return NULL;
 
-        if (q->n_items <= 0)
+        if (idx >= q->n_items)
                 return NULL;
 
-        return q->items[0].data;
+        return q->items[idx].data;
 }
 
 void *prioq_pop(Prioq *q) {

diff --git a/src/basic/prioq.h b/src/basic/prioq.h
index bba5c7caa49ca6d047b799f2c8c441e759757361..1fb57bfa4ca433b3c6010fd0def8ebb6414de4f4 100644 (file)
--- a/src/basic/prioq.h
+++ b/src/basic/prioq.h
@@ -19,8 +19,14 @@ int prioq_put(Prioq *q, void *data, unsigned *idx);
 int prioq_remove(Prioq *q, void *data, unsigned *idx);
 int prioq_reshuffle(Prioq *q, void *data, unsigned *idx);
 
-void *prioq_peek(Prioq *q) _pure_;
+void *prioq_peek_by_index(Prioq *q, unsigned idx) _pure_;
+static inline void *prioq_peek(Prioq *q) {
+        return prioq_peek_by_index(q, 0);
+}
 void *prioq_pop(Prioq *q);
 
+#define PRIOQ_FOREACH_ITEM(q, p)                                \
+        for (unsigned _i = 0; (p = prioq_peek_by_index(q, _i)); _i++)
+
 unsigned prioq_size(Prioq *q) _pure_;
 bool prioq_isempty(Prioq *q) _pure_;

diff --git a/src/test/test-prioq.c b/src/test/test-prioq.c
index bc5fdd15b269b19afe958705d3ce86587f6abe6c..53c9e090a70235bb3a3d0289a207f1e5841314b1 100644 (file)
--- a/src/test/test-prioq.c
+++ b/src/test/test-prioq.c
@@ -69,6 +69,11 @@ static void test_struct(void) {
         assert_se(q = prioq_new((compare_func_t) test_compare));
         assert_se(s = set_new(&test_hash_ops));
 
+        assert_se(prioq_peek(q) == NULL);
+        assert_se(prioq_peek_by_index(q, 0) == NULL);
+        assert_se(prioq_peek_by_index(q, 1) == NULL);
+        assert_se(prioq_peek_by_index(q, (unsigned) -1) == NULL);
+
         for (i = 0; i < SET_SIZE; i++) {
                 assert_se(t = new0(struct test, 1));
                 t->value = (unsigned) rand();
@@ -79,6 +84,17 @@ static void test_struct(void) {
                         assert_se(set_consume(s, t) >= 0);
         }
 
+        for (i = 0; i < SET_SIZE; i++)
+                assert_se(prioq_peek_by_index(q, i));
+        assert_se(prioq_peek_by_index(q, SET_SIZE) == NULL);
+
+        unsigned count = 0;
+        PRIOQ_FOREACH_ITEM(q, t) {
+                assert_se(t);
+                count++;
+        }
+        assert_se(count == SET_SIZE);
+
         while ((t = set_steal_first(s))) {
                 assert_se(prioq_remove(q, t, &t->idx) == 1);
                 assert_se(prioq_remove(q, t, &t->idx) == 0);